Eddy Formation in the Tropical Atlantic Induced by Abrupt Changes in the Meridional Overturning Circulation

Author:

Goes Marlos1,Marshall David P.2,Wainer Ilana3

Affiliation:

1. Department of Geosciences, The Pennsylvania State University, University Park, Pennsylvania

2. Atmospheric, Oceanic and Planetary Physics, University of Oxford, Oxford, United Kingdom

3. Departamento de Oceanografia Fisica, Universidade de Sao Paulo, Sao Paulo, Brazil

Abstract

Abstract The variability of the meridional overturning circulation (MOC) in the upper tropical Atlantic basin is investigated using a reduced-gravity model in a simplified domain. Four sets of idealized numerical experiments are performed: (i) switch-on of the MOC until a fixed value when a constant northward flow is applied along the western boundary; (ii) MOC with a variable flow; (iii) MOC in a quasi-steady flow; and (iv) shutdown of the MOC in the Northern Hemisphere. Results from experiments (i) show that eddies are generated at the equatorial region by shear instability and detached northward; eddies are responsible for an enhancement of the mean flow and the variability of the MOC. Results from experiments (ii) show a transitional behavior of the MOC related to the eddy generation in interannual–decadal time scales as the Reynolds number varies due to the variations in the MOC. In experiments (iii), a critical Reynolds number Rec around 30 is found, above which eddies are generated. Experiments (iv) demonstrate that even after the collapse of MOC in the Northern Hemisphere, eddies can still be generated and carry energy across the equator into the Northern Hemisphere; these eddies act to attenuate the impact of the MOC shutdown on short time scales. The results described here may be particularly pertinent to ocean general circulation models in which the Reynolds number lies close to the bifurcation point separating the laminar and turbulent regimes.

Publisher

American Meteorological Society

Subject

Oceanography

Reference44 articles.

1. Thermohaline circulation, the Achilles heel of our climate system: Will man-made CO2 upset the current balance?;Broecker;Science,1997

2. A high-resolution simulation of the wind- and thermohaline-driven circulation in the North Atlantic Ocean.;Bryan,1989

3. Nonlinear disturbances of the western boundary currents.;Cessi;J. Phys. Oceanogr.,1993

4. Global seiching of thermocline waters between the Atlantic and the Indian-Pacific Ocean Basins.;Cessi;Geophys. Res. Lett.,2004

5. Geographical variability of the first baroclinic Rossby radius of deformation.;Chelton;J. Phys. Oceanogr.,1998

Cited by 3 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

1. Symmetric Instability in Cross-Equatorial Western Boundary Currents;Journal of Physical Oceanography;2021-06

2. The Tropical Atlantic Observing System;Frontiers in Marine Science;2019-05-10

3. Propagation of North Atlantic Deep Water Anomalies;Journal of Physical Oceanography;2018-08

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3